Re: [RFC/PATCH] cpuset: cpuset irq affinities

Paul Jackson
2008-03-03T17:41:44Z

Peter wrote:
> The system group can overlap with anything that does need system services.

I suppose IRQs need to overlap like this, but cpusets often can't
overlap like this.

If a system has the cgroup hierarchy you draw:

/cgroup
/cgroup/system
/cgroup/system/boot

/cgroup/big_honking_app
/cgroup/rt_domain

this must not force the cpuset hierarchy to be:

/dev/cpuset
/dev/cpuset/system
/dev/cpuset/system/boot

/dev/cpuset/big_honking_app
/dev/cpuset/rt_domain

I guess this means IRQs cannot be added to the cpuset subsystem
of cgroups. Rather they have to be added to some other cgroup
subsystem, perhaps a new one just for IRQs.

In perhaps the most common sort of cpuset hierarchy:

/dev/cpuset
/dev/cpuset/boot
/dev/cpuset/batch_sched
/dev/cpuset/big_honking_app
/dev/cpuset/rt_domain

none of boot or its siblings overlap.

--
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <pj@sgi.com> 1.940.382.4214